The United States of America As Represented by the Administrator of the

John C Evans, Jr

An-Ti Chai

Chandra P Goradia

Henry W Brandhorst, Jr

George A Mazaris

Larry R Scudder

A high voltage multijunction solar cell comprises a plurality of discrete voltage generating regions, or unit cells, which are formed in a single semiconductor wafer (10) and are connected together so that the voltages of the individual cells are additive. The unit cells comprise doped regions of opposite conductivity types (30, 32) separated by a gap. The method includes forming V-shaped grooves (16) in the wafer and thereafter orienting the wafer so that ions of one conductivity type can be implanted in one face (e.g., 16a) of the groove while the other face (e.g., 16b) is shielded. A metallization layer (22) is applied and selectively etched away to provide connections between the unit cells.

High voltage V-groove solar cell

A heat transparent high intensity solar cell has improved efficiency. A surface of each solar cell (10,16,22) has a plurality of grooves (12,14,18,20,24). Each groove has a vertical face (26,30) and a slanted face (28,32) that is covered by a reflecting metal (34,36). Light rays (38,40) are reflected from the slanted face through the vertical face where they traverse a photovoltaic junction (60). As the light rays travel to the slanted face of an adjacent groove, they again traverse the junction. The underside of the reflecting coating directs the light rays toward the opposite surface of solar cell as they traverse the junction again. When the light rays travel through the solar cell and reach the saw toothed grooves on the under side, the process of reflection and repeatedly traversing the junction again takes place. The light rays ultimately emerge from the solar cell as shown in FIG. 4. These solar cells are particularly useful at very high levels of insolation because the infrared or heat radiation passes through the cells without being appreciably absorbed to heat the cell.

Heat transparent high intensity high efficiency solar cell

A high voltage multijunction solar cell is provided wherein a plurality of discrete voltage generating regions or unit cells are formed in a single generally planar semiconductor body (12). The unit cells comprise a doped regions (20, 22) of opposite conductivity type separated by a gap or undiffused region (24). Metal contacts (26) connect adjacent cells together in series so that the output voltages of the individual cells are additive. In some embodiments, doped field regions (14) separated by gap (16) overlie the unit cells but the cells may be formed in both faces of the wafer (FIG. 2).

High voltage planar multijunction solar cell

A method is provided for making a high voltage multijunction solar cell which comprises a plurality of discrete voltage generating regions, or unit cells, which are formed in a single semiconductor wafer (10) and are connected together so that the voltages of the individual cells are additive. The unit cells comprise doped regions of opposite conductivity types (30, 32) separated by a gap. The method includes forming V-shaped grooves (16) in the wafer and thereafter orienting the wafer so that ions of one conductivity type can be implanted in one face (e.g., 16a) of the groove while the other face (e.g., 16b) is shielded. A metallization layer (22) is applied and selectively etched away to provide connections between the unit cells.

Method of making a high voltage V-groove solar cell

A monolithie multijunction solar cell is modified by fabricating an integrated circuit inverter on the back of the cell to produce a device capable of generating an alternating current output. In another embodiment, integrated circuit power conditioning electronics is incorporated in a module containing a solar cell power supply.

Solar cell system having alternating current output

A heterojunction or Schottky barrier photovoltaic device comprising a conductive base metal layer compatible with and coating predominately the exposed surface of the p-type substrate of the device such that a back surface field region is formed at the interface between the device and the base metal layer, a transparent, conductive mixed metal oxide layer in integral contact with the n-type layer of the heterojunction or Schottky barrier device having a metal alloy grid network of the same metal elements of the oxide constituents of the mixed metal oxide layer embedded in the mixed metal oxide layer, an insulating layer which prevents electrical contact between the conductive metal base layer and the transparent, conductive metal oxide layer, and a metal contact means covering the insulating layer and in intimate contact with the metal grid network embedded in the transparent, conductive oxide layer for conducting electrons generated by the photovoltaic process from the device.

Method for fabricating solar cells having integrated collector grids

A transparent, conductive collector layer containing conductive metal channels is formed as a layer on a photovoltaic substrate by coating a photovoltaic substract with a conductive mixed metal layer; attaching a heat sink having portions protruding from one of its surfaces which define a continuous pattern in combination with recessed regions among said protruding portions to said substrate such that said protruding portions of said heat sink are in contact with the conductive layer of said substrate; and Heating said substrate while simultaneously oxidizing the portions of the conductive layer exposed to a gaseous oxidizing substance forced into said recessed regions of said heat sink, thereby creating a transparent metal oxide layer on said substrate containing a continuous pattern of highly conductive metal channels in said layer.

Solar cell collector and method for producing same

Diffusants are applied onto semiconductor solar cell substrates using screen printing techniques. The method is applicable to square and rectangular cells and can be used to apply dopants of opposite types to the front and back of the substrate. Then, simultaneous diffusion of both dopants can be performed with a single furnace pass.

Application of semiconductor diffusants to solar cells by screen printing

A heterojunction or Schottky barrier photovoltaic device comprising a conductive base metal layer compatible with and coating predominately the exposed surface of the p-type substrate of the device such that a back surface field region is formed at the interface between the device and the base metal layer, a transparent, conductive mixed metal oxide layer in integral contact with the n-type layer of the heterojunction or Schottky barrier device having a metal alloy grid network of the same metal elements of the oxide constituents of the mixed metal oxide layer embedded in the mixed metal oxide layer, an insulating layer which prevents electrical contact between the conductive metal base layer and the transparent, conductive metal oxide layer, and a metal contact means convering the insulating layer and in intimate contact with the metal grid network embedded in the transparent, conductive oxide layer for conducting electrons generated by the photovoltaic process from the device.

Solar cells having integral collector grids

A solar cell panel is fabricated by photoetching a pattern of collector grid systems with appropriate interconnections and bus bar tabs into a glass or plastic sheet. These regions are then filled with a first, thin conductive metal film followed by a layer of a mixed metal oxide, such as InAsO.sub.x or InSnO.sub.x. The multiplicity of solar cells are bonded between the protective sheet at the sites of the collector grid systems and a back electrode substrate by conductive metal filled epoxy to complete the fabrication of an integrated solar panel.

Method for producing solar energy panels by automation

A transparent, conductive collector layer containing conductive metal channels is formed as a layer on a photovoltaic substrate by coating a photovoltaic substrate with a conductive mixed metal layer; attaching a heat sink having portions protruding from one of its surfaces which define a continuous pattern in combination with recessed regions among said protruding portions to said substrate such that said protruding portions of said heat sink are in contact with the conductive layer of said substrate; and Heating said substrate while simultaneously oxidizing the portions of the conductive layer exposed to a gaseous oxidizing substance forced into said recessed regions of said heat sink, thereby creating a transparent metal oxide layer on said substrate containing a continuous pattern of highly conductive metal channels in said layer.

Growing community of inventors

North Olmsted, OH, United States of America

John C Evans, Jr